Lecture @ the E4D ETH Winter School 2015 on Global Water Challenges

1. Andrea Castelletti
Dipartimento di Elettronica, Informazione, e Bioingegneria, Politecnico di Milano, Milano, Italy
Institute of Environmental Engineering ETH-Z, Zurich
Dammed or damned: the role of hydropower in
the water and energy nexus
E4D
Winter
School
2005
3-­‐23
January
2015
Son La Dam
Vietnam, 2012

2. Outline
• What is water-energy nexus?
• Hydropower and the nexus
• An added challenge: global change
• What can we do: the soft path approach
• Case study
• Conclusions

3. Outline
• What is water-energy nexus?
• Hydropower and the nexus
• An added challenge: global change
• What can we do: the soft path approach
• Case study
• Conclusions

4. The water and energy (watergy) nexus
water needs
energy
Water production, processing,
distribution, and end-use require
energy
• Extraction
• Treatment (drinking/waste)
• Distribution
• Use
energy needs
water
Energy production
requires water
• Hydropower
• Thermo electric cooling
• Mineral Extraction and refining
• Fuel production (fossil, non-
fossil, and biofuel)
• Emission control
Source: adapted from WWAP, 2014

5. Energy needs water
Source: IEA, 2012
• Energy production consumes 15% of water withdrawals
More than 580 billion m3 withdrawn every year (the average
annual discharge of the River Gange), of which 66 billion is
consumed)

6. Energy needs water
Source: IEA, 2012
• Energy production consumes 15% of water withdrawals
More than 580 billion m3 withdrawn every year (the average
annual discharge of the River Gange), of which 66 billion is
consumed)
• Thermal power plants (roughly 80% of global electricity
production) is responsible for:
• 43% of total water withdrawals in Europe,
• 50% in the US, and
• more than 10% in China.

7. Energy needs water
Section II – Water for Energy
Figure 23. Flow Chart of Embedded Water in Energy
Extraction
Mining, drilling
(oil, natural gas)
Biomass
Wastewater
Collection,
treatment and
discharge or reuse
Resource
Raw Material
Refining
Coal, petrol,
natural gas,
uranium, biofuels
Renewable
Energy
Wind, solar,
hydroelectric, tidal
Water Source
(e.g., lakes, rivers,
aquifiers, sea)
Energy Recycling
Cogeneration,
desalination
Transport &
Transmission
Pipelines,
waterways
End Use
Industrial
Commercial
Residential
Public Utilities
Transportation
Energy
Generation
Discharge Water
Transportation Fuels, Natural Gas
Note: Water inputs and outputs may be in different water bodies.
1. Cooling Technologies
1.1 Once-Through (Open-Loop) Cooling
Once-through cooling uses an ample supply of water
(from an ocean, river, lake, cooling pond or canal) to
run through the system’s heat exchanger to condense
the low-pressure steam at the exhaust of the turbines
high-temperature events and competition for water
resources. This is particularly exacerbated by the fact
that electricity demand is disproportionately high in
water-scarce areas such as the Southwest. Moreover,
Source: adapted from Wilkinson, 2000

8. Energy needs water
country’s
mptive). In
wals are used
oberg, 2005).
fraction is
withdrawals
n 3.3.1).
implications
nd examine
s of primary
ve industries
quantities of
eams need to
That water
he water
uses. Water
mining,
environment.
and gas
water per
he water
nal fossil fuels
uels.
primary
35 (IEA,
gress of ‘clean’
he world’s
FIGURE
3.1 Water withdrawals and consumption vary for
fuel production
* The minimum is for primary recovery; the maximum is for
secondary recovery. ** The minimum is for in-situ production,
the maximum is for surface mining. *** Includes carbon dioxide
101
Sugar cane
ethanol
Corn
ethanol
Soybean
Rapeseed
Palm oil
Lignocellulosic
Refined oil
Coal-to-liquids
Gas-to-liquids
Refined oil
Refined oil
Shale
gas
Coal
Conventional
gas
Litres per toe
<1
Withdrawal
Consumption
102
103
104
105
106
107
biodiesel
biodiesel
biodiesel
ethanol****
(EOR)***
(oil sands)**
(conventional)*
‘Water use efficien
India’. ]
For power plants wi
cooling system used
required. The three
open-loop, closed-l
systems exist, but ar
once-through, cool
water, fresh and sali
all the water to the
evaporation (Figure
less water withdraw
use of cooling towe
much higher water
et al., 2011).
Dry cooling does no
use of fans that mov
in automobiles). Po
option is often the l
cooling is less effect
installations do ope
China, Morocco, So
because these system
have parasitic losses
estimated that cost
for air cooled conde
competitive in mos
2012).
The volatility of pric
fuels for thermal po* Includes trough, tower and Fresnel technologies using tower, dry
FIGURE
3.8 Water use for electricity generation by
cooling technology
Nuclear
Fossil steam
Gas CCGT
Nuclear
Fossil steam
Gas CCGT
Nuclear
Fossil steam (CCS)
Fossil steam
Coal IGCC (CCS)
Coal IGCC
Gas CCGT (CCS)
Gas CCGT
Gas CCGT
Geothermal**
Litres per MWh
Wind
Solar PV
CSP*
Other/noneDryCoolingtowerCooling
pond
Once-
through
10
1
<1 10
2
10
3
10
4
10
5
10
6
Withdrawal
Consumption
power plant, the less heat has to be dissipated, thus
less cooling is required (Delgado, 2012). Older power
Primary production Energy generation
Source: IEA, 2012

9. Water needs energy
• Water related energy consumption is estimated to be about
2-3% of worldwide energy production

10. Water needs energy
• California consumes approximately 20%of the state’s electricity,
and 30% of the state’s non-power plant natural gas
(source: California Energy Commission)
• Running the hot water faucet for 5 minutes uses about the same
amount of energy as burning a 60-watt bulb for 14 hours
(source US-EPA)
• Water related energy consumption is estimated to be about
2-3% of worldwide energy production

11. Water needs energy
Section I – Energy for Water
Figure 11. Water Flowchart (Highlighting Source)
Source
Lakes, reservoirs,
aquifers
Water
Treatment
Water
Distribution
Water Extraction
and Conveyance
Recycled Water
Distribution
Recycled Water
Treatment
End Use
Agriculture
Energy Production
Industrial
Commercial
Residential
Leaks
Wastewater
Treatment
Energy
Production
Biogas
Nitrous oxide
Net Loss
Discharge to
ocean
Net Loss
Evaporation
Transpiration
Wastewater
Collection
Leaks
Storm Water
Recycled Water
Leaks
Leaks
Discharge Water
Direct Use (Irrigation, energy production, industrial)
Raw
Water
Raw
Water
Potable
Water
Wastewater
Discharge Water
Biosolids
Biogas
Source: Adapted from Wilkinson, 2000
1. Water Conveyance
Research on the energy use of water conveyance systems, which are used to import water to these areas,
Source: adapted from Wilkinson, 2000

12. Water needs energy
such as reverse osmosis, require larger amounts
(1.5–3.5 kWh/m3
). Water for agriculture generally requires
little or no treatment, so energy requirements are mainly for
pumping (Section 6.4). Globally, the amount of energy used
for irrigation is directly related to the enormous quantities
of water required for irrigation and the irrigation methods
used.
(400%),
mestic use
be noted that
outh Africa;
Development;
e water’
GE). OECD
ricity
Livestock
2000 2050
World
Note: This diagram does not incorporate critical elements such as
the distance the water is transported or the level of efficiency, which
vary greatly from site to site.
Source: WBSCD (2009, fig. 5, p. 14, based on source cited therein).
FIGURE2.2 Amount of energy required to provide 1 m3
water safe for human consumption from
various water sources
STATUS, TRENDS AND CHALLENGES
Source: WBSCD, 2009
Amount of energy for 1 m3 of safe water

13. Water needs energy
64
(Lazarova et al., 2012).quality (and in the case of groundwater, its depth), and
Note: GWRS, groundwater replenishment system; WWTP, wastewater treatment plant.
Source: Lazarova et al. (2012, fig. 23.1, p. 316, adapted from sources cited therein). © IWA Publishing, reproduced with permission.
FIGURE
7.3 Typical energy footprint of the major steps in water cycle management with examples from different
treatment plants using specific technologies
5
4
3
2
1
0
2.5 kWh/m3
,
State Water
Project, CA
0.35 kWh/m3
,
Strass WWTP,
Austria
2.5
1.5
0.24 0.3 0.4
0.6
1.4
2.5 2.5
1.5
2.5
0.3
1.2
5.0
4.0
0.1 0.2 0.05
0.16
0.24 0.25 0.3
0.5
0.2
1.0
1.4 1.4
1.1
0.53 kWh/m3
,
GWRS, Orange
County, CA
2.9 kWh/m3
,
Desalination
Ashkelon,
Israel
Water
conveyance
Water
treatment
Water
distribution
Preliminary
treatment
Trickling
filters
Activated
sludge
Activated
sludge with
nitrification
Membrane
bioreactor
Water reuse Brackish
water
desalination
Seawater
desalination
Rainwater
harvesting
Energyconsumption(kWh/m3
)
THEMATIC FOCUSCHAPTER 7
Source: Lazarova et al. 2012
Typical energy footprint of the major steps in the water cycle

14. Implications and benefits of the nexus
• Nexus implies that decisions made in one domain affect the
other and viceversa

15. Implications and benefits of the nexus
• Nexus implies that decisions made in one domain affect the
other and viceversa
• Policies that benefit one domain can pose significant risks
and detrimental effects to the other (e.g. biofuels) …

16. Implications and benefits of the nexus
• Nexus implies that decisions made in one domain affect the
other and viceversa
• Policies that benefit one domain can pose significant risks
and detrimental effects to the other (e.g. biofuels) …
• … but can also generate co-benefit (e.g. energy attracts
greater political attention than water in many countries)

17. How serious is the water constraint?
VIETNAM/PHILIPPINES
In 2010 an El Nino
induced drought
caused electricity
shortages and rationing
for several months

18. How serious is the water constraint?
VIETNAM/PHILIPPINES
In 2010 an El Nino
induced drought
caused electricity
shortages and rationing
for several months
CHINA
In 2011 drought limited
generation along the
Yangtze river with
higher coal demand
and prices and
electricity rationing

19. How serious is the water constraint?
INDIA
In 2012 delayed monsoon
reduced hydropower and
raised energy demand for
irrigation causing 2 days
black out for 600 milion
people
VIETNAM/PHILIPPINES
In 2010 an El Nino
induced drought
caused electricity
shortages and rationing
for several months
CHINA
In 2011 drought limited
generation along the
Yangtze river with
higher coal demand
and prices and
electricity rationing

20. How serious is the water constraint?
INDIA
In 2012 delayed monsoon
reduced hydropower and
raised energy demand for
irrigation causing 2 days
black out for 600 milion
people
VIETNAM/PHILIPPINES
In 2010 an El Nino
induced drought
caused electricity
shortages and rationing
for several months
CALIFORNIA
In 2012 and 2014 drought
caused significant
hydropower energy loss
due to reduced
snowpack and limited
precipitation
CHINA
In 2011 drought limited
generation along the
Yangtze river with
higher coal demand
and prices and
electricity rationing

21. How serious is the water constraint?
INDIA
In 2012 delayed monsoon
reduced hydropower and
raised energy demand for
irrigation causing 2 days
black out for 600 milion
people
VIETNAM/PHILIPPINES
In 2010 an El Nino
induced drought
caused electricity
shortages and rationing
for several months
CALIFORNIA
In 2012 and 2014 drought
caused significant
hydropower energy loss
due to reduced
snowpack and limited
precipitation
CHINA
In 2011 drought limited
generation along the
Yangtze river with
higher coal demand
and prices and
electricity rationing
US MID-WEST
In 2006 heat wave forced
substantial reduction of nuclear
energy production to control
temperature in the Missisipi river

22. To know more …
VOLUME 1
Report

23. Outline
• What is water-energy nexus?
• Hydropower and the nexus
• An added challenge: global change
• What can we do: the soft path approach
• Case study
• Conclusions

24. Hydropower and the nexus
Source: WWAP, 2014 and IEA, 2013
Trends in world electricity generation by energy source
0
4 000
8 000
12 000
16 000
20 000
24 000
1971 1975 1980 1985 1990 1995 2000 2005 2011
Fossil thermal Nuclear Hydro Other*
TWh
Oil 24.6%
Coal and peat
38.3%
Coal and peat
41.3%
Hydro 21.0% Hydro 15.8%
Nuclear 3.3%
Nuclear
11.7%
Natural gas
12.2%
Natural gas
21.9%
Oil 4.8%
Other* 0.6%
Geothermal
0.3%
Biofuels, waste
1.9%
Solar PV 0.3%
Wind 2.0%
and other sources
(a) 1971–2011
(b) 1973: 6 115 TWh total
(c) 2011: 22 126 TWh total
Note: Excludes pumped storage. *‘Other’includes geothermal, solar, wind, biofuels and waste, and heat. PV, solar photovoltaic.
INDICATOR
13
(a)
(b) 1973 (c) 2011
Trend in electricity generation by energy source

25. Role of dams and reservoirs
in out
time, spacetime, space
discharge
discharge

26. The first dam (2700 BC)
Sadd-el-Kafara, Egypt
2700-2600 BC
Source: http://www.hydriaproject.net, last visit 31.12.14

27. Dam development in the XIX and XX century
Source: B. Lehner- McGill University

28. Dam development in the XIX and XX century

29. Dams by purpose
Source: WWAP, with data from IEA (2013).
IEA (International Energy Agency). 2013. World Indicators. World energy statistics and balances database. Paris, OECD/IEA.
doi: 10.1787/data-00514-en (Accessed Dec 2013)
(a) Single purpose dams
(b) Multi purpose dams
Source: WWAP, with data from ICOLD (n.d.).
ICOLD (International Commission on Large Dams). n.d. General Synthesis. Paris, ICOLD.
http://www.icold-cigb.net/GB/World_register/general_synthesis.asp (Accessed Dec 2013)
INDICATOR
19
2000 2001 2002 2003 2004 2005 2006 2007 2011
World OECD Europe Africa Asia (excluding China)
China (PR of China and Hong Kong) India Russian Federation United States of America
2008 2009 2010
Use of dams by purpose
Hydropower 18.0%
Water supply
12.0%
Navigation and
fish farming 0.6%
Irrigation
50.0%
Other 5.0%
Recreation
5.0%
Flood control
10.0%
Irrigation
24.0%
Navigation and
fish farming 8.0%
Recreation
12.0%
Other 4.0%
Flood control
20.0%
Hydropower
16.0%
Water supply 17.0%
(a) (b)
Source: WWAP, 2014 and ICOLD, 2014
single purpose multi purpose

30. Dams by purpose and country
Source: Lehner, 2011

31. Capacity chart of hydropower
HYPERBOLE
Annual Conference, September 30 2014 8
Capacity Chart of Hydroelectric Power Station
ρ= ×hP Q gH
Source: Avelan, 2014
DISCHARGE
HYDRAULICHEAD

32. Capacity chart of hydropower
HYPERBOLE
Annual Conference, September 30 2014 8
Capacity Chart of Hydroelectric Power Station
ρ= ×hP Q gH
Source: Avelan, 2014
DISCHARGE
HYDRAULICHEAD

33. Capacity chart of hydropower
HYPERBOLE
Annual Conference, September 30 2014 8
Capacity Chart of Hydroelectric Power Station
ρ= ×hP Q gH
Source: Avelan, 2014
DISCHARGE
HYDRAULICHEAD

34. Largest hydropower plants (the first 25)
2
1
2
1
1
4
4
11
canada
U.S.
venezuela
paraguay
brazil
pakistan
russia
china

35. Hydropower impact
Is HP generating conflicts with other water uses and
ecosystem services?
As a non-consumptive water use HP is not removing water
from the system …
… but for evaporation or seepage
So, should we consider HP a clean, green and fair energy
production source?

36. Impacted sectors
People
Resettlement
HYDROPOWER
Environment
Water Quality
Sediment
balance
GHG emission Competing uses
• Agriculture
• Water supply
• Energy (cooling)
• Recreation
• ….
Navigation

37. Inter-sector conflicts: the Colorado river
COLORADO RIVER, US-Mexico
Salt intrusion (violet)
Glen Canyon Dam
• Hydropower production ( 6 large dams)
• Agriculture (Imperial Valley)
• Water supply

38. Inter-sector conflicts: the Colorado river
COLORADO RIVER, US-Mexico
Salt intrusion (violet)
Glen Canyon Dam
• Hydropower production ( 6 large dams)
• Agriculture (Imperial Valley)
• Water supply

39. Inter-sector conflicts: the Red River basin, Vietnam
Hanoi
HoaBinh
TaBu
LaiChau
TamDuong
NamGiang
MuongTe
VuQuang
YenBai
BaoLacHaGiang
BacMe
VIETNAM
CHINA
LAOS
CAMBODIA
THAILAND
Da
Thao Lo
Integrated Management of Red-Thai Binh Rivers System (IMRR) funded by the Italian
Ministry of Foreign Affairs http://www.imrr.info/

40. Inter-sector conflicts: the Red River basin, Vietnam
Basin wide, anthropogenic changes over the last ~ 60 years
1960 1970 1980 1990 2000 2010 Future
LAND USE CHANGE RESERVOIR CONSTRUCTION SEDIMENT MINING

41. Inter-sector conflicts: the Red River basin, Vietnam
Focus on 3 stations
Red
River:
Son
Tay
Ha
Noi
Duong
River:
Thuong
Cat

42. Inter-sector conflicts: the Red River basin, Vietnam
Morphologic changes aggravate water scarcity & endanger vital
infrastructure

43. Inter-sector conflicts: the Red River basin, Vietnam
Irriga@on
deficits
Saltwater
intrusion
Before Now

44. Making things trickier: most rivers are transboundary …
Trans-national river basins collect 60% of the world freshwater.

45. … and power-asymmetric

46. Outline
• What is water-energy nexus?
• Hydropower and the nexus
• An added challenge: global change
• What can we do: the soft path approach
• Case study
• Conclusions

47. Earth is warming
source: IPCC, 2007

48. Climate is changing:
extremes will be more frequent
source: IPCC, 2007

49. Climate is changing and so does the water cycle:
natural availability is declining
Change in water natural availability, not considering production
technology, access to water, etc
2050 vs [1961-90]
source: Arnell, 2004

50. Evidences from the future
source: National GeographicRivers run dry (Colorado)

51. Forzieri et al. , HESS, 107(25), 2014.
Climate is changing and so does the water cycle:
wetter in the north, drier in the south
40% reduction in minimum stream flow by the 2080s in the Iberian Peninsula, Italy
and the Balkan Region

52. Society is changing as well:
+ people
source: UNEP, 2008

53. Society is changing as well:
+ people ++ energy demand
Global energy demand is expected to grow by more than one-third over the period to
2035, with China, India and the Middle Eastern countries accounting for about 60% of the
increase.

54. Society is changing as well:
+ people ++ energy demand ++ water demand
Change in water withdrawal and consumption by 2025:
more extraction less consumptive
source: UNESCO, 2001

55. Society is changing as well:
+ people ++ energy demand ++ water demand
Shift to alternate energy will require more water + load balancing
e.g.
• 1st generation biofuel consume 20 times as much water for mile traveled compare to
gasoline
• All-electric vehicles will place added strains on utilities: 1 mile three time water than with
gasoline power (King and Webber, 2008)
source: IEA, 2014
OECD/IEA,2012
newly built nuclear power plants that use once-through cooling (for instance, some that
are constructed inland in China), which expands water withdrawals for nuclear generators
by a third. Consumption of water in the world’s power sector rises by almost 40%, boosted
by increased use of wet tower cooling in thermal capacity. Increasing shares of gas-fired
and renewable generation play a significant role in constraining additional water use in
many regions, as global electricity generation grows by some 0% over 2010-2035, much
more than water withdrawal or consumption by the sector.
Figure 17.7 ⊳ Global water use for energy production in the New Policies
Scenario by fuel and power generation type
0
100
200
300
400
500
600
700
800
2010 2020 2035
bcm
Withdrawal
0
20
40
60
80
100
120
140
2010 2020 2035
bcm
ConsumpƟon
Biofuels
Fossil fuels
Bioenergy
Nuclear
Oil
Gas
Coal
Fuels:
Power:
Energy-related water use rises as a direct consequence of steeply increasing global biofuels
supply, which triples in the New Policies Scenario on government policies that mandate
the use of biofuels. Water withdrawals for biofuels increase in line with global supply, from
25 bcm to 110 bcm over 2010-2035. owever, consumption increases from 12 bcm to
almost 50 bcm during that time, equalling the water consumption for power generation by
the end of the Outlook period. These higher water requirements for biofuels production
stem from the irrigation needs for feedstock crops for ethanol and biodiesel – primarily
Global water use for energy by fuel and power generation source

56. Society is changing as well:
+ people ++ energy demand ++ water demand
Load balancing from renewable energy production
Pumped storage is the largest-capacity form of grid energy storage
available in the world (99% of bulk storage capacity worldwide,
representing around 127,000 MW).
Energy efficiency varies in practice between 70% and 80%.
The EU has 38.3 GW net capacity (36.8% of world capacity) out of a total of 140 GW of
hydropower.
Japan has 25.5 GW net capacity (24.5% of world capacity).

57. Global change is shrinking the pie
global
change

58. Outline
• What is water-energy nexus?
• Hydropower and the nexus
• An added challenge: global change
• What can we do: the soft path approach
• Case study
• Conclusions

59. React/adapt to change: re-expand the pie
global
change

60. Accessible freshwater is limited
Salt Water
98%
Fresh Water
2%
Worldwide distribution:
98% salt water
2% fresh water
Surface waters (lake and rivers)
are just 0.01% of the total
freshwater
Groundwater
12%
Rivers & Lakes
0.01%
Ice
87%

61. What can we do? We should adapt, of course
ADAPTATION MEASURE: Adjustment in natural or human systems in
response to actual or expected climatic stimuli or their effects, which
moderates harm or exploits beneficial opportunities.
Source: European Climate Adaptation Platform - EC
source: googling“adaptation program” – images

62. Supply-side adaptation: investing in centralized, large-scale
physical infrastructures, and centralized water management
systems
source: WRI 2003
The 20th century approach
Water supply expansion is constrained (PEAK WATER)
P.H. Gleick & M. Palanniappan, PNAS, 107(25), 2010.
des of projections
s that planners consis-
y assumed continued,
ven accelerated, expo-
al growth in total water
nd (Fig. 3). Some pro-
ons were that water
rawals would have to
and even quadruple in
ng years, requiring ad-
nal dams and diver-
on previously un-
d water resources in
te or pristine areas
declared off-limits to
lopment. Proposals
been made to flood the
d Canyon, dam the
zon, and divert Siberi-
nd Alaskan rivers to
ern population centers.
stead, as Figs. 3 and 4
, total water withdraw-
egan to stabilize in the
s and 1980s, and
ruction activities be-
o slow as the unquan-
but real environmental and social
of dams began to be recognized. More
tly, the economic costs of the
ional hard path have also risen to
s that society now seems unwilling
able to bear. The most cited estimate
he cost of meeting future
A New Approach for Water
What is required is a “soft path,” one that
continues to rely on carefully planned and
managed centralized infrastructure but
complements it with small-scale decentral-
ized facilities. The soft path for water
strives to improve the pro-
ductivity of water use rather
than seek endless sources of
new supply. It delivers wa-
ter services and qualities
matched to users’ needs,
rather than just delivering
quantities of water. It ap-
plies economic tools such as
markets and pricing, but
with the goal of encouraging
efficient use, equitable dis-
tribution of the resource,
and sustainable system op-
eration over time. And it in-
cludes local communities in
decisions about water man-
agement, allocation, and use
(21–23). As Lovins noted for the
energy industry, the industrial
dynamics of this approach are
very different, the technical risks
are smaller, and the dollars
risked far fewer than those of the
hard path (24).
Rethinking water use
means reevaluating the objec-
tives of using water. Hard-path planners erro-
neously equate the idea of using less water, or
failing to use much more water, with a loss of
well-being. This is a fallacy. Soft-path planners
believe that people want to satisfy demands for
goods and services, such as food, fiber, and
Fig. 4. Construction of large reservoirs worldwide in the 20th century. Average
numbers of reservoirs with volume greater than 0.1 km3
built by decade,
through the late 1990s, are normalized to dams per year for different periods.
Note that there was a peak in construction activities in the middle of the 20th
century, tapering off toward the end of the century. The period 1991 to 1998
is not a complete decade; note also that the period 1901 to 1950 is half a
century. “Other regions” include Latin America, Africa, and Oceania (46).
source: Gleick, 2003

63. Soft is wiser: the “soft path”
Supply and demand integrated management: improving
overall productivity of water by making water management
more efficient rather than seeking new sources of supply
P.H. Gleick, Nature, 418, 373, 2002.
P.H. Gleick, Science, 302, 1524-1528, 2003.
by
• EXPLORE THE TRADE-OFFs
• Distributed and coordinated management
• Better informed decisions (pervasive monitoring)
• Smart economics (option contracts, ensurances)
• Participatory decision-making
• ….

64. Outline
• What is water-energy nexus?
• Hydropower and the nexus
• An added challenge: global change
• What can we do: the soft path approach
• Case study
• Conclusions

65. An example: Lake Como
Reservoirs
Lake Como 247 Mm3
Alpine hydropowers 545 Mm3
Catchment area
Lake Como 4500 km2
Stakeholders
Hydropower producers:
25% national hydropower production
Farmers:
5 districts for a total area of 1400 km2
Hydropower reservoir
Power plant
Como city
Penstock
River Adda
River Adda
Legend
Lario
Lario catchment
River
Irrigated area
0 10 20 30 40 505
Kilometers

66. DISTRILAKE enhancing water resources management
efficiency and sustainability via integration and coordination
Hydropower reservoir
Power plant
Como city
Penstock
River Adda
River Adda
Legend
Lario
Lario catchment
River
Irrigated area
0 10 20 30 40 505
Kilometers
Virtual and physical storages
SNOW
PACK
HYDROPOWER
RESERVOIRS
LAKE
COMO
GROUNDWATER
GREEN
WATER

67. DISTRILAKE alpine hydro – lake como
Hydropower reservoir
Power plant
Como city
Penstock
River Adda
River Adda
Legend
Lario
Lario catchment
River
Irrigated area
0 10 20 30 40 505
Kilometers
Virtual and physical storages
SNOW
PACK
HYDROPOWER
RESERVOIRS
LAKE
COMO
GROUNDWATER
GREEN
WATER
Anghileri, D. et al. Journal of Water Resources Planning and
Management, 139(5), 492–500, 2013

68. Hydropower reservoir
Power plant
Como city
Penstock
River Adda
River Adda
Legend
Lario
Lario catchment
River
Irrigated area
0 10 20 30 40 505
Kilometers
Virtual and physical storages
SNOW
PACK
HYDROPOWER
RESERVOIRS
LAKE
COMO
GROUNDWATER
GREEN
WATER
Anghileri, D. et al. Journal of Water Resources Planning and
Management, 139(5), 492–500, 2013
R2
R1
DISTRILAKE alpine hydro – lake como

69. Hydropower reservoir
Power plant
Como city
Penstock
River Adda
River Adda
Legend
Lario
Lario catchment
River
Irrigated area
0 10 20 30 40 505
Kilometers
R2
R1
J F M A M J J A S O N D
0
10
20
30
40
Flow[m
3
/s]
Inflow Release
J F M A M J J A S O N D
50
100
150
200
250
Flow[m
3
/s]
Time [days]
(a)
(b)
FIG. 2. Historical inflow (dashed) and release (solid) of the hydropower reservoir R1
(a) and lake Como (b) (14-days moving median over the period 1996-2005).
22
R1
J F M A M J J A S O N D
50
100
150
200
250
Demand[m
3
/s]
(a)
J F M A M J J A S O N D
0
500
1000
1500
2000
2500
Price[euro/MW]
(b)
J F M A M J J A S O N D
−20’000
−10’000
0
10’000
20’000
30’000
Revenue[euro/day]
(c)
Time [days]
FIG. 5. (a): Yearly pattern of water demand. (b): Yearly pattern of the energy price
(each colour band represents the energy price in the j-th most profitable hour). (c):
Di↵erence in daily hydropower revenue (14-days moving average over years 1996-2005)
between centralized policy C6 and uncoordinated UC.
energy price
J F M A M J J A S O N D
50
100
150
200
250
Demand[m
3
/s]
(a)
2000
2500
]
(b)
water demand
J F M A M J J A S O N D
0
10
20
30
40
Flow[m
3
/s]
Inflow Release
J F M A M J J A S O N D
50
100
150
200
250
Flow[m
3
/s]
Time [days]
(a)
(b)
FIG. 2. Historical inflow (dashed) and release (solid) of the hydropower reservoir R1
(a) and lake Como (b) (14-days moving median over the period 1996-2005).
Lake Como
DISTRILAKE alpine hydro – lake como
Anghileri, D. et al. Journal of Water Resources Planning and
Management, 139(5), 492–500, 2013

70. Lake
Como
Lake
Como
r
s1
s2
s3
u1
u2
u3
R2
R1
R2
R1
hydropower plant
irrigated area
H2
H1
H3
H2
H1
H3
q3
q2
q1
q3
q2
q1
s1
s2
s3
u2
u3
u1
m1
m2
m
3
(•)
m(•)(•)
(•)
UNCOORDINATED CENTRALIZED
(a) (b)
r
FIG. 3. The model scheme under uncoordinated (left) and centralized (right) man-
agement.
23
800 900 1000 1100 1200 1300 1400 1500 1600
460’000
470’000
480’000
490’000
Irrigation deficit [m
3
/s]
2
Hydropowerrevenue[euro/day]
H
ab
C6
C5
C4
C3
C2
C1
CO2 CO1 UCUC
UN-COORDINATED

71. Lake
Como
Lake
Como
r
s1
s2
s3
u1
u2
u3
R2
R1
R2
R1
hydropower plant
irrigated area
H2
H1
H3
H2
H1
H3
q3
q2
q1
q3
q2
q1
s1
s2
s3
u2
u3
u1
m1
m2
m
3
(•)
m(•)(•)
(•)
UNCOORDINATED CENTRALIZED
(a) (b)
r
FIG. 3. The model scheme under uncoordinated (left) and centralized (right) man-
agement.
23
800 900 1000 1100 1200 1300 1400 1500 1600
460’000
470’000
480’000
490’000
Irrigation deficit [m
3
/s]
2
Hydropowerrevenue[euro/day]
H
ab
C6
C5
C4
C3
C2
C1
CO2 CO1 UCUC
UN-COORDINATED
Lake
Como
r
s1
s2
s3
u1
u2
u3
R2
R1
R2
R1
hydropower plant
irrigated area
H2
H1
H3
H2
H1
H3
q3
q2
q1
q3
q2
s2
s3
u2
u3
m
3
m(•)
(•)
NATED CENTRALIZED
(b)
cheme under uncoordinated (left) and centralized (right) man-
CENTRALIZED (SOCIAL PLANNER)

72. Lake
Como
Lake
Como
r
s1
s2
s3
u1
u2
u3
R2
R1
R2
R1
hydropower plant
irrigated area
H2
H1
H3
H2
H1
H3
q3
q2
q1
q3
q2
q1
s1
s2
s3
u2
u3
u1
m1
m2
m
3
(•)
m(•)(•)
(•)
UNCOORDINATED CENTRALIZED
(a) (b)
r
FIG. 3. The model scheme under uncoordinated (left) and centralized (right) man-
agement.
23
800 900 1000 1100 1200 1300 1400 1500 1600
460’000
470’000
480’000
490’000
Irrigation deficit [m
3
/s]
2
Hydropowerrevenue[euro/day]
H
ab
C6
C5
C4
C3
C2
C1
CO2 CO1 UCC6
C5
C4
C3
C2
C1
UC
UN-COORDINATED
Lake
Como
r
s1
s2
s3
u1
u2
u3
R2
R1
R2
R1
hydropower plant
irrigated area
H2
H1
H3
H2
H1
H3
q3
q2
q1
q3
q2
s2
s3
u2
u3
m
3
m(•)
(•)
NATED CENTRALIZED
(b)
cheme under uncoordinated (left) and centralized (right) man-
CENTRALIZED (SOCIAL PLANNER)

73. Lake
Como
Lake
Como
r
s1
s2
s3
u1
u2
u3
R2
R1
R2
R1
hydropower plant
irrigated area
H2
H1
H3
H2
H1
H3
q3
q2
q1
q3
q2
q1
s1
s2
s3
u2
u3
u1
m1
m2
m
3
(•)
m(•)(•)
(•)
UNCOORDINATED CENTRALIZED
(a) (b)
r
FIG. 3. The model scheme under uncoordinated (left) and centralized (right) man-
agement.
23
800 900 1000 1100 1200 1300 1400 1500 1600
460’000
470’000
480’000
490’000
Irrigation deficit [m
3
/s]
2
Hydropowerrevenue[euro/day]
H
ab
C6
C5
C4
C3
C2
C1
CO2 CO1 UCC6
C5
C4
C3
C2
C1
UC
UN-COORDINATED
Lake
Como
r
s1
s2
s3
u1
u2
u3
R2
R1
R2
R1
hydropower plant
irrigated area
H2
H1
H3
H2
H1
H3
q3
q2
q1
q3
q2
s2
s3
u2
u3
m
3
m(•)
(•)
NATED CENTRALIZED
(b)
cheme under uncoordinated (left) and centralized (right) man-
CENTRALIZED (SOCIAL PLANNER)
?

74. Lake
Como
R2
R1
hydropower plant
irrigated area
H2
H1
H3
q3
q2
q1
s1
s2
s3
u2
u3
u1
m1
m2
m
3
(•)
(•)
(•)
COORDINATED
r
coordination
mechanism
FIG. 4. The model scheme under coordinated management.
24
800 900 1000 1100 1200 1300 1400 1500 1600
460’000
470’000
480’000
490’000
Irrigation deficit [m
3
/s]
2
Hydropowerrevenue[euro/day]
H
ab
C6
C5
C4
C3
C2
C1
CO2 CO1 UCC6
C5
C4
C3
C2
C1
UC
COORDINATED
Lake
Como
r
s1
s2
s3
u1
u2
u3
R2
R1
R2
R1
hydropower plant
irrigated area
H2
H1
H3
H2
H1
H3
q3
q2
q1
q3
q2
s2
s3
u2
u3
m
3
m(•)
(•)
NATED CENTRALIZED
(b)
cheme under uncoordinated (left) and centralized (right) man-
CENTRALIZED (SOCIAL PLANNER)
?

75. Lake
Como
R2
R1
hydropower plant
irrigated area
H2
H1
H3
q3
q2
q1
s1
s2
s3
u2
u3
u1
m1
m2
m
3
(•)
(•)
(•)
COORDINATED
r
coordination
mechanism
FIG. 4. The model scheme under coordinated management.
24
800 900 1000 1100 1200 1300 1400 1500 1600
460’000
470’000
480’000
490’000
Irrigation deficit [m
3
/s]
2
Hydropowerrevenue[euro/day]
H
ab
C6
C5
C4
C3
C2
C1
CO2 CO1 UCC6
C5
C4
C3
C2
C1
UC
COORDINATED
Lake
Como
r
s1
s2
s3
u1
u2
u3
R2
R1
R2
R1
hydropower plant
irrigated area
H2
H1
H3
H2
H1
H3
q3
q2
q1
q3
q2
s2
s3
u2
u3
m
3
m(•)
(•)
NATED CENTRALIZED
(b)
cheme under uncoordinated (left) and centralized (right) man-
CENTRALIZED (SOCIAL PLANNER)
0 0.5 1 1.5 2 2.5 3 3.5
x 10
8
0
2
4
6
8
10
12
Lake reservoir [m3
]
Releasedecision(R1)[m
3
/s]
C6
UC
Constraint
FIG. 7. Hydropower release decision of reservoir R1 as a function of lake storage
under centralized policy C6 (red circles) and uncoordinated policy UC (blue points).
?

76. DISTRILAKE enhancing water resources management
efficiency and sustainability via integration and coordination
Hydropower reservoir
Power plant
Como city
Penstock
River Adda
River Adda
Legend
Lario
Lario catchment
River
Irrigated area
0 10 20 30 40 505
Kilometers
Virtual and physical storages
SNOW
PACK
HYDROPOWER
RESERVOIRS
LAKE
COMO
GROUNDWATER
GREEN
WATER

77. DISTRILAKE lake como - greenwater
Hydropower reservoir
Power plant
Como city
Penstock
River Adda
River Adda
Legend
Lario
Lario catchment
River
Irrigated area
0 10 20 30 40 505
Kilometers
Virtual and physical storages
SNOW
PACK
HYDROPOWER
RESERVOIRS
LAKE
COMO
GROUNDWATER
GREEN
WATER
Galelli. et al. Environmental Modelling and Software,
25, 209–222, 2010

78. Hydropower reservoir
Power plant
Como city
Penstock
River Adda
River Adda
Legend
Lario
Lario catchment
River
Irrigated area
0 10 20 30 40 505
Kilometers
J F M A M J J A S O N D
50
100
150
200
250
Demand[m
3
/s]
(a)
J F M A M J J A S O N D
0
500
1000
1500
2000
2500
Price[euro/MW]
(b)
J F M A M J J A S O N D
−20’000
−10’000
0
10’000
20’000
30’000
Revenue[euro/day]
(c)
Time [days]
water demand
J F M A M J J A S O N D
0
10
20
30
40
Flow[m
3
/s]
Inflow Release
J F M A M J J A S O N D
50
100
150
200
250
Flow[m
3
/s]
Time [days]
(a)
(b)
FIG. 2. Historical inflow (dashed) and release (solid) of the hydropower reservoir R1
(a) and lake Como (b) (14-days moving median over the period 1996-2005).
22
Lake Como
water demand = Σ water use
concessions
[ - Irrigation
- Industrial water supply
- Run-off river hydro ]
Is that the actual water demand?
DISTRILAKE lake como - greenwater
Galelli. et al. Environmental Modelling and Software,
25, 209–222, 2010

79. DISTRILAKE lake como - greenwater
green water resource
blue water resource
blue water resource
blue water flow
saturated
zone
unsaturated
zone
green water flow
rain
• BLUE WATER: surface and ground water
• GREEN WATER: water in the unsaturated root zone
Falkenmark, M. and Rockström, Journal of Water Resources
Planning and Management, 132(3), 129–132, 2006
Galelli. et al. Environmental Modelling and Software,
25, 209–222, 2010

80. Author's personal copy
0 200 400 600 800 1000 1200 1400
0
200
400
600
800
1000
1200
1400
J
i
(m
3
/s)
2
Jf
(m2
/g/a)
Naive OCP Frontier
Reduced OCP Frontier
Naive OCP Utopia point
Reduced OCP Utopia point
historical management
C
B
B’
C’
AU’U
U
U’
h
h
Fig. 7. Image of the Pareto-Frontiers of the Naive (dashed line) and Reduced (solid line) OCP obtained by simulating the Lake Como system over the period 1993–20
historical performance, while points U’ and U are the Utopia points of the Naive and Reduced OCP respectively. The meaning of the labelled points is explained
S. Galelli, R. Soncini-Sessa / Environmental Modelling & Software 25 (2010) 209–222
Hydropower reservoir
Power plant
Como city
Penstock
River Adda
River Adda
Legend
Lario
Lario catchment
River
Irrigated area
0 10 20 30 40 505
Kilometers
J F M A M J J A S O N D
50
100
150
200
250
Demand[m
3
/s]
(a)
J F M A M J J A S O N D
0
500
1000
1500
2000
2500
Price[euro/MW]
(b)
J F M A M J J A S O N D
−20’000
−10’000
0
10’000
20’000
30’000
Revenue[euro/day]
(c)
Time [days]
water demand
J F M A M J J A S O N D
0
10
20
30
40
Flow[m
3
/s]
Inflow Release
J F M A M J J A S O N D
50
100
150
200
250
Flow[m
3
/s]
Time [days]
(a)
(b)
FIG. 2. Historical inflow (dashed) and release (solid) of the hydropower reservoir R1
(a) and lake Como (b) (14-days moving median over the period 1996-2005).
22
Lake Como
Blue water
Blue & Green
water
irrigation deficit
floodedarea
DISTRILAKE lake como - greenwater
Galelli. et al. Environmental Modelling and Software,
25, 209–222, 2010

81. Author's personal copy
0 200 400 600 800 1000 1200 1400
0
200
400
600
800
1000
1200
1400
J
i
(m
3
/s)
2
Jf
(m2
/g/a)
Naive OCP Frontier
Reduced OCP Frontier
Naive OCP Utopia point
Reduced OCP Utopia point
historical management
C
B
B’
C’
AU’U
U
U’
h
h
Fig. 7. Image of the Pareto-Frontiers of the Naive (dashed line) and Reduced (solid line) OCP obtained by simulating the Lake Como system over the period 1993–20
historical performance, while points U’ and U are the Utopia points of the Naive and Reduced OCP respectively. The meaning of the labelled points is explained
S. Galelli, R. Soncini-Sessa / Environmental Modelling & Software 25 (2010) 209–222
Hydropower reservoir
Power plant
Como city
Penstock
River Adda
River Adda
Legend
Lario
Lario catchment
River
Irrigated area
0 10 20 30 40 505
Kilometers
J F M A M J J A S O N D
50
100
150
200
250
Demand[m
3
/s]
(a)
J F M A M J J A S O N D
0
500
1000
1500
2000
2500
Price[euro/MW]
(b)
J F M A M J J A S O N D
−20’000
−10’000
0
10’000
20’000
30’000
Revenue[euro/day]
(c)
Time [days]
water demand
J F M A M J J A S O N D
0
10
20
30
40
Flow[m
3
/s]
Inflow Release
J F M A M J J A S O N D
50
100
150
200
250
Flow[m
3
/s]
Time [days]
(a)
(b)
FIG. 2. Historical inflow (dashed) and release (solid) of the hydropower reservoir R1
(a) and lake Como (b) (14-days moving median over the period 1996-2005).
22
Lake Como
Blue water
Blue & Green
water
irrigation deficit
floodedarea
DISTRILAKE lake como - greenwater
saving 75 Mm3 per year
= ¼ of lake Como
Galelli. et al. Environmental Modelling and Software,
25, 209–222, 2010

82. DISTRILAKE lake como - greenwater
Galelli. et al. Environmental Modelling and Software,
25, 209–222, 2010
Blue water

83. DISTRILAKE lake como - greenwater
Galelli. et al. Environmental Modelling and Software,
25, 209–222, 2010
Blue water

84. DISTRILAKE lake como - greenwater
Galelli. et al. Environmental Modelling and Software,
25, 209–222, 2010
Blue water

85. DISTRILAKE lake como - greenwater
Galelli. et al. Environmental Modelling and Software,
25, 209–222, 2010
Blue water
Blue & green water

86. DISTRILAKE lake como - greenwater
Galelli. et al. Environmental Modelling and Software,
25, 209–222, 2010
Blue water
Blue & green water

87. Hydropower reservoir
Power plant
Como city
Penstock
River Adda
River Adda
Legend
Lario
Lario catchment
River
Irrigated area
0 10 20 30 40 505
Kilometers
DISTRILAKE lake como - greenwater
Galelli. et al. Environmental Modelling and Software,
25, 209–222, 2010
Network upgrade to supply on demand
FlumeGateTM by RUBICON WATER

88. Hydropower reservoir
Power plant
Como city
Penstock
River Adda
River Adda
Legend
Lario
Lario catchment
River
Irrigated area
0 10 20 30 40 505
Kilometers
Downscaling
Catchment
model
Water system
model
Performance
indicators
Management
model
Regional
climate
scenario
Local
climate
scenario
Reservoir
inflow
scenario
Operation
policy
Impacts on
water
resources
Anghileri, D. et al. Hydrology and Earth System
Sciences, 15(6), 2025–2038, 2011
Uncertain futures and decision making

89. Scenario-based approach
possible future technological development and
socio-economic development of the antropic
forcings (IPCC 2007)

90. Scenario-based approach
from Le Treut et al., 2007 from www.wmo.int

91. Scenario-based approach
from www.wmo.int
from100 km to 25 km and higher resolution

92. Scenario-based approach
HBV model [Bergstrom, 1976]
from the atmosphere to local hydrological cycle

93. Scenario-based approach

94. Scenario-based approach
Wilby & Dessai, Weather, 65(7), 180-185, 2010

95. 500 1000 1500 2000 2500 3000 3500 4000 4500 5000
−5
−4.5
−4
−3.5
−3
−2.5
−2
x 10
5
Irrigation deficit (m
3
/s)
2
−Hydropowerrevenue(euro)
* Future optimal
management policies
The impact of CC on Lake Como

96. Adaptation is better than myopic
500 1000 1500 2000 2500 3000 3500 4000 4500 5000
−5
−4.5
−4
−3.5
−3
−2.5
−2
x 10
5
Irrigation deficit (m
3
/s)
2
−Hydropowerrevenue(euro)
* Future optimal
management policies

97. Future is non stationary
500 1000 1500 2000 2500 3000 3500 4000 4500 5000
−5
−4.5
−4
−3.5
−3
−2.5
−2
x 10
5
Irrigation deficit (m3
/s)2
−Hydropowerrevenue(euro)
2071-­‐2080
2081-­‐2090
2091-­‐2100

98. Future is deeply uncertain
500 1000 1500 2000 2500 3000 3500 4000 4500 5000
−5
−4.5
−4
−3.5
−3
−2.5
−2
x 10
5
Irrigation deficit (m
3
/s)
2
−Hydropowerrevenue(euro)
HadRM3H
REMO
HIRHAM
RCAO
CHRM
PROMES
CLM
Uncertainty from different
RCM projections

99. Conclusions
• Present day water and energy systems are tightly intertwined
• Hydropower has a role in the nexus
• Global change is challenging future hydropower operation
• Soft adaptation measures should be first considered to better
exploit the potential of existing infrastructures
• Designing and implementing those measures require a trully
mulidisciplinary approach
• Sationarity is dead and the future uncertain: implications for
planning

100. That’s all